RTEMS Intel i386 Applications Supplement
The maximum period with interrupts disabled within RTEMS is less than 13.0 microseconds including the instructions which disable and re-enable interrupts. The time required for the i386 to generate an interrupt using the int instruction, vectoring to an interrupt handler, and for the RTEMS entry overhead before invoking the user's interrupt handler are a total of 12 microseconds. These combine to yield a worst case interrupt latency of less 13.0 + 12 microseconds. [NOTE: The maximum period with interrupts disabled within RTEMS was last calculated for Release 3.1.0.]
It should be noted again that the maximum period with interrupts disabled within RTEMS is hand-timed. The interrupt vector and entry overhead time was generated on the Force Computers CPU386 benchmark platform using the int instruction as the interrupt source.
RTEMS Intel i386 Applications Supplement
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